R. f. seal for electromagnetic wave radiation shielding enclosure



April 4, 1967 E. P. LA KAFF 3,312,769 R-F. SEAL! FOR ELECTROMAGNETICWAVE RADIATION SHIELDING ENCLOSURE Filed 00%. 29, 1965 2 Sheets-Sheet 1INVENTOR Edward P. Lu Kuff ATTORNEY April 4, 1967 E. P. LA KAFF 3,

' R F SEAL FOR ELECTROMAGNETIC WAVE RADIATION SHIELDING ENCLOSURE 2Sheets-Sheet 2 Filed Oct. 29, 1965 mGE INVENTOR Edward P. Lo KoffATTORNEY United States Patent 3,312,769 R.F. SEAL FOR ELECTROMAGNETICWAVE RADI- ATION SHIELDING ENCLOSURE Edward Peter La Kali, Corvallis,Oreg., assignor to Borg- Warner Corporation, Chicago, Ill., acorporation of Illinois Filed Oct. 29, 1965, Ser. No. 505,678 9 Claims.(Cl. 17435) .This invention relates to electromagnetic wave radiationshielding of enclosures and more particularly to shielding means for thejoints of adjacent panels of radio frequency shielding enclosures.

A principal object of the invention is to provide a radio frequencyshielding strip assembly for the joints between adjacent panels of aradio frequency shielding enclosure in which the panels are of easilydeformable sheet material.

Another object of the invention is to provide a shielding apparatus forthe joints of shielding panels in which shielding material is brought tobear against the adjacent marginal edges of adjacent panels despite thetendency of the panel edges to deform and become displaced with re spectto each other.

A further object of the invention is to provide shielding apparatus ofthe stated type wherein means are provided for efiecting a continuoussealing pressure throughout the length of the panel edges with thepressure being applied only at spaced points.

Another object of the invention is to provide electromagnetic waveshielding apparatus for the joints of adjacent panels of a radiofrequency shielding enclosure in which the shielding material isresiliently biased into conductive relation with the adjacent marginaledges of adjacent shielding panels.

These and other objects of the invention will become more apparent asthe description proceeds with reference to the accompanying drawings, inwhich:

FIGURE 1 is a view in perspective of a shielding strip assembly made inaccordance with the present invention and illustrated in operativerelation to supporting surfaces;

FIGURE 2 is an elevational sectional view taken substantially on line 22of FIGURE 1;

FIGURE 3 is a plan view, partly in section, of a shielding stripassembly made in accordance with the present invention;

FIGURE 4 is a front elevational view of the strip assembly of FIGURE 3;

FIGURE 5 is a sectional plan view of a modified form of a mounting anglefor the shielding strip assembly of the present invention;

FIGURE 6 is a view similar to FIGURE 3 but showing a modified form ofthe present invention; and,

FIGURE 7 is a vertical sectional view taken substantially on line 77 ofFIGURE 6.

Referring to the drawings and more particularly to FIGURES l and 2 theshielding strip assembly of the present invention is indicated generallyby reference numeral 10 and includes a mounting member 12, which isillustrated as being of channel configuration, and has a plurality ofthreaded openings 14 for reception of set screw 16. Secured to theoutside surface of the base of the mounting member 12, at each end, is achannel member 18 of relatively thin sheet metal, such as stainlesssteel or the like. 18, and extending beyond the ends thereof as clearlyillustrated in FIGURE 1, is a resilient core 20, desirably of neoprenesponge or the like, which is surrounded by a metallic mesh 22, of analloy of nickel and copper such as of Monel metal or the like.

A pair of T-shaped brackets 24 each having a tang 26 may be secured, byany suitable means, to a suitable sup- Mounted within'the channel member"Ice 2 porting surface in spaced relation to the ends of a panel jointafter the tangs 26 have been received within the ends of the channelmember 18, as illustrated in FIG- URE 4. The channel member 18 issecured, as by spot welding or the like, at each end to the mountingmember 12. The entire expanse of the channel member between the spotwelds may be bowed away from the channel member 12 by tightening thescrews 16 to bring the mesh 22 into resilient conductive relation withthe marginal edges of panels 26 and 28, as illustrated clearly in FIG-URE 2. An important advantage of this construction is that pressure onthe channel member is exerted only at spaced points but the pressure ofthe mesh 22 tends to be continuous throughout the length of the marginaledges of the panels. In this way, there are no gaps for possible leakageof radio frequency radiation.

In FIGURES 3 and 4 is illustrated an elevational view of the shieldingstrip of the invention illustrating clearly the manner in which thechannel member 18 is forced into engagement with the marginal edges of apanel illustrated in dot and dash lines. The brackets 24 may be shapedto conform to any desired use. FIGURE 3 illustrates the brackets 24 asbeing secured, by means of cap screws 30 to an L-shaped frame member 32.In FIG- URE 5 is illustrated an alternate form of frame member to whichthe brackets 24 may be secured.

In FIGURES 6 and 7 is illustrated a modified form of the presentinvention in which a support member 12a is utilized in lieu of thesupport member 12 of the principal form of the invention. The supportmember 12a is of tubular construction, substantially rectangular incrosssection and functions much in the same manner as support member 12.In FIGURES 6 and 7 like reference numerals refer to like parts in theprincipal form of the invention. The support member may be particularlyuseful in instances where the enclosure panels are of limited thicknesssuch as in the order of t" and the like.

The shielding device of the present invention exhibits importantadvantages over shielding devices heretofore known. For instance, theflexibility of the channel member ,18 and the action of the screws 16permits the mesh 22 to be resiliently biased into electricallyconductive engagement with the marginal edges of adjacent enclosurepanels despite a tendency of the panels to depart from the same plane. Acontinuous shielding pressure is maintained throughout the length of themarginal edges of the panel with pressure exerted only at .spaced pointsthroughout the length of the channel member 18. The support members .12and 12a, besides providing reaction points for the screws 16, functionto provide additional rigidity to the entire joint. It will beappreciated that metals other than Monel may be substituted in the mesh22. So also, other metals may be substituted for the stainless steel ofthe channel member 18 and other resilient materials, such aspolyurethane foam, may be substituted for the neoprene of the core 20.

It is to be understood that the invention is not to be limited to thespecific constructions and arrangements shown and described, except onlyinsofar as the claims may be so limited, as it will be understood tothose skilled in the art that changes may be made without departing fromthe principles of the invention.

What is claimed is:

1. Apparatus for sealing joints of adjacent panels of an electromagneticwave radiation shielding enclosure comprising an elongated mountingmember, a channel member secured to said mounting member, resilient coremounted in said channel member, a metallic mesh surrounding saidresilient core, and means for biasing said channel member away from saidmounting member so that said mesh-clad core is forced into conductiverelation with the marginal edges of adjacent panels when said panels arebrought into contact therewith.

2. A sealing assembly for the joints of adjacent panels of anelectromagnetic wave radiation shielding enclosure comprising a bodyportion having a mounting member, a channel member secured to saidmounting member at each end thereof, a pair of T-shaped brackets adaptedto be secured to a supporting surface and each having a tab adapted tobe received in an end of said channel member, a resilient core disposedin said channel member, a metallic mesh surrounding said resilient core,and means for displacing said channel member with respect to saidmounting member so that the metallic mesh is brought into resilientengagement with the marginal edges of the panels throughout the lengthof the joint when said panels are brought into contact therewith.

3. A shielding strip assembly in accordance with claim 2, wherein saidlast-named means comprises a plurality of screws threadably received insaid mounting member in longitudinally spaced relation, said screwsbeing in abutment with said channel member so as to bias said channelmember away from said mounting member and into firmelectricallyconductive relation to the marginal edges of enclosure panels. 1

4. A shielding strip assembly in accordance with claim 2, wherein saidtangs are secured to said channel member.

5. A strip assembly in accordance with claim 4, wherein said resilientcore is of neoprene and the like.

6. A shielding strip assembly in accordance with claim 5, wherein saidchannel member is of stainless steel and the like.

7. A shielding strip assembly in accordance with claim 5, wherein saidmounting member is of channel crosssection.

8. A shielding strip assembly in accordance with claim 5, wherein saidmounting member is tubular and of rectangular cross-section.

9. A shielding strip assembly in accordance with claim 2, wherein saidmesh is an alloy of nickel and copper.

LEWIS H. MYERS, Primary Examiner.

D. L. CLAY, Examiner

1. APPARATUS FOR SEALING JOINTS OF ADJACENT PANELS OF AN ELECTROMAGNETICWAVE RADIATION SHIELDING ENCLOSURE COMPRISING AN ELONGATED MOUNTINGMEMBER, A CHANNEL MEMBER SECURED TO SAID MOUNTING MEMBER, RESILIENT COREMOUNTED IN SAID CHANNEL MEMBER, A METALLIC MESH SURROUNDING SAIDRESILIENT CORE, AND MEANS FOR BIASING SAID CHANNEL MEMBER AWAY FROM SAIDMOUNTING MEMBER SO THAT SAID MESH-CLAD CORE IS FORCED INTO CONDUCTIVERELATION WITH THE MARGINAL EDGES OF ADJACENT PANELS WHEN SAID PANELS AREBROUGHT INTO CONTACT THEREWITH.